This application claims benefit of priority from Japanese Patent Application No. 2000-278962 filed Sep. 13, 2000, the entire contents of which are herein incorporated by reference.
1. Field of the Invention
The present invention is directed to a sputtering device for producing a predetermined film on the surface of a substrate and, more particularly, it relates to a sputtering device suitable for film deposition using a plurality of targets of different materials.
2. Discussion of Related Art
In the description of the background of the present invention that follows reference is made to certain structures and methods, however, such references should not necessarily be construed as an admission that these structures and methods qualify as prior art under the applicable statutory provisions. Applicants reserve the right to demonstrate that any of the referenced subject matter does not constitute prior art with regard to the present invention.
The production of predetermined films on the surface of a substrate is widely performed in the manufacture of electronic devices, such as large scale integrated circuits (LSI) and display devices such as liquid crystal displays (LCD). Sputtering devices are widely used for film production because they can produce a quality film at high speed. An important characteristic demanded of sputtering devices is the production of uniform films. Generally, non-uniform film thickness and film quality lowers performance of the product that is manufactured using said film.
The difficulty of forming a uniform sputtering discharge in the direction of the surface of the substrate is one factor contributing to the reduction of film uniformity. In addition, where a magnet mechanism is provided for magnetron discharge, forming of a uniform magnetic field from the magnet mechanism in the direction of the substrate can be difficult and is a factor contributing to the reduction of film uniformity.
To overcome this drawback and others and to ensure film uniformity, a structure that rotates the substrate about an axis of revolution coaxial with the center of the target can be used. However, some manufacturing processes do not enable rotation of the substrate, i.e., for mechanical reasons.
An object of the present invention, which is designed to solve the problems noted above, possesses technological significance in that it can produce a uniform film without need for rotation of the substrate.
A sputtering device is provided in which at least one target is sputtered by sputtering discharge to produce a film of target material on at least a first surface of a substrate. The sputtering device has a principal rotating mechanism that rotates the at least one target about an axis of revolution coaxial with the central axis of the substrate. The target is positioned offset from the central axis of the substrate. In another aspect of the present invention, a plurality of targets are provided on a circumference coaxial with the axis of revolution. Power for the sputtering discharge on each of the plurality of targets is supplied and can be independently controlled by a power supply system.
The sputtering device can be further provided with a magnet mechanism for the magnetron discharge of the sputtering discharge. The principal rotating mechanism can integrate rotation of the targets with the magnet mechanism. The magnet mechanism can form a magnetic field asymmetrical to a central axis of the target and can be rotated by an auxiliary rotating mechanism about the central axis of the target. The magnet mechanism can be rotated by using the rotational power of the principal rotating mechanism.
The targets and the principal rotating mechanism can form a cathode unit disposed in vertical opposition to each of the first and second surfaces of the substrate.
In an additional embodiment, the targets can be positioned inclined at a predetermined angle to the substrate.